[Effect of deliberate hypotension with PGE1 on PaO2 in pediatric patients].

We compared the effect of deliberate hypotension with PGE1 on PaO2 between pediatric and adult patients. Seven children, aged 3-9 yrs and 10 adults, aged 35-65 yrs who were scheduled for elective head and neck surgeries were studied. Anesthesia was maintained with enflurane, 50% N2O in oxygen and supplemental infusion of fentanyl. Ventilation was controlled to maintain PaCO2 at 35-40 mmHg. Hypotension was induced with continuous infusion of PGE1 and the systolic blood pressure was maintained at 70% of the presurgical value. Blood gases were measured three times, i.e. before, during, and after hypotension. The hypotension in adults caused a significant reduction in PaO2. In children, on the contrary, PaO2 was not affected by the hypotension. The results suggest that intrapulmonary shunting is smaller in children than in adults during PGE1-induced hypotension.